Kinetic model of trapped finite-temperature binary condensates

Abstract

We construct a nonequilibrium theory for the dynamics of two interacting finite-temperature atomic Bose-Einstein condensates and use it to numerically estimate the relative rates of the arising collisional processes near equilbrium. The condensates are described by dissipative Gross-Pitaevskii equations, coupled to quantum Boltzmann equations for the thermal atoms. The density-density interactions between atoms in different components facilitate a number of transport processes of relevance to sympathetic cooling: in particular, considering realistic miscible and immiscible trapped atomic Rb87-K41 and Rb87-Rb85 condensate mixtures, we highlight the dominance of an intercomponent scattering process associated with collisional "exchange" of condensed and thermal atoms between the components close to equilibrium.